While most competitors are “dieting down” with very restrictive diets that limit carbs to very low levels I keep my carb intake levels up until 7-10 days pre-competition! It’s the unique combination of proper nutrient timing, carb-cycling and nutritional cleansing that puts carbs to work FOR ME versus AGAINST ME. Here is the REAL DEEP SCIENCE behind why it’s not only unnecessary but may be detrimental to deprive the body of carbs for prolonged periods. There’s no arguing that lowering carb intake has been effective for leaning up, but what if there was an even better way to build/maintain MORE MUSCLE while getting LEANER!!!

The consumption of large amounts of protein by athletes and bodybuilders is not a new practice (1). Recent evidence suggests that increased protein intakes for endurance and strength-trained athletes can increase strength and recovery from exercise (2, 3, 4). In healthy adult men consuming small frequent meals providing protein at 2.5g/kg/day, there was a decreased protein breakdown, and increased protein synthesis of up to 63%, compared with intakes of 1g/kg/day (5). Subjects receiving 1g/kg/day underwent muscle protein breakdown with less evident changes in muscle protein synthesis. Some evidence suggests, however, that a high protein diet increases leucine oxidation (6, 7), while other data demonstrate that the slower digestion rate of protein (8, 9), and the timing of protein ingestion (with resistance training) (10) promote muscle protein synthesis.

One important role of dietary carbohydrate (through pyruvate) is in anaplerosis, the replenishing of Krebs cycle intermediates, (or tricarboxylic acid cycle intermediates—TCAI). The primary role of this cycle is to generate reduced forms of the enzymes NADH and FADH2, transferring high energy electrons to the mitochondrial electron transport chain for use in the resynthesis of ATP (11). IN OTHER WORDS FOR THE MORE EFFICIENT PRODUCTION OF ENERGY! Five of the intermediates of Krebs cycle are involved in additional reactions which involve amino acids and will be limited if insufficient carbohydrate is available. Oxaloacetate and α-ketoglutarate are used in the synthesis of several amino acids such as phosphoenolpyruvate. Heme synthesis uses succinyl CoA, glutamine synthesis draws upon α-ketoglutarate, and citrate is the source of acetyl-CoA in the cystol and is used for the synthesis of lipids and amino acids (12, 13).

Adequate dietary carbohydrate during exercise is thus critical, because its availability is inversely related to the rate of exercise protein catabolismOR MUSCLE TISSUE BREAKDOWN (14), hence adequate carbohydrate can prevent cataplerosis, the reverse of anaplerosis, which takes place in the absence of sufficient pyruvate (from carbohydrate). Gluconeogenesis (THE CREATION OF GLUCOSE FROM OTHER SOURCES SUCH AS AMINO ACIDS FROM MUSCLE TISSUE & DIET) can be considered cataplerotic and can result in a “drain” of Krebs cycle intermediates (13), which may result in a decreased production of ATP, and an increased muscle protein breakdown. There may be a critical minimum intake of carbohydrate to provide a sufficient flux of pyruvate to maintain anaplerosis (3), and prevent muscle protein breakdown via gluconeogenesis.

This has practical significance to fitness enthusiasts, athletes, and bodybuilders where 150-400g of protein can be consumed per day (16-18), especially if consumed at the expense of sufficient carbohydrate. In elite athletes it has been clearly established that low glycogen availability for exercising skeletal muscles leads to fatigue more rapidly in prolonged or intense exercise (19, 20). Other studies show the time until the onset of fatigue during high-intensity exercise in untrained individuals consuming diets deficient in carbohydrate is shortened (21-24), however similar results are not found in trained individuals (25). In high-intensity resistance training, fatigue may also be associated with carbohydrate depletion (26).While high protein diets have focused on protein and its value in building lean muscle and preventing protein breakdown, it is vitally important for athletes to understand that high protein consumption at the expense of sufficient amounts of carbohydrate can be potentially detrimental to lean muscle.